Pole-changer.



Q1. ERICKSON.

POLE CHANGER.

APPLICATION FILED Aue.2s, 1906.

1,162,992. Patented Dec. 7, 1915.

2 SHEETSSHEET I.

C. 3. ERiCKSON.

POLE CHANGER.

APPLICATION FILED AUG.23. 1906.

1,162,992, Patented Dec. 7, 1915.

2 SHEETSSHEET 2.

UNITED STATES PATENT oEEioE.

CHARLES J'. ERICKSON, OF CHICAGO, ILLINOIS, ASSIGNOR, BY MESNE ASSIGNMENTS, TO FIRST TRUST AND SAVINGS BANK, TRUSTEE, OF CHICAGO, ILLINOIS.

POLE-CHANGER.

Specification of Letters Patent.

Patented Dec. 7, 1915.

Application filed August 23, 1906. Serial No. 331,701.

To all whom it may concern:

Be it known that I, CHARLES J. ERICKSON,

a citizen of the United States of America, and resident of Chicago, Cook county, Illinois, have invented a certain new and useful Improvement in Pole-Changers, of which the following is a specification.-

My invention relates to pole changers or devices by which a battery current can be converted into an alternating current. Devices of this character are used, for example, in telephone systems in ringing the subscribers bells, and more especially for selectively operating the bells on a party line. This is for the reason that a pole changer can be readily adjusted to vary the frequency of the current, thus making it possible to economically supply alternating currents of diflerent frequencies for selectively operating the bells on a party line. It will be understood, however, that my improved pole changer can be employed for any suitable or desired purpose.

In certain respects my present invention is in the nature of an improvement on the pole changer disclosed in my prior application Serial No. 330,192, filed August 11, 1906. In my said prior application the operating circuit for energizing the electromagnet is independent of or distinct'from the generating circuit which includes the primary of the transformer or inductioncoil, although, of course, both circuits include the battery or some portion thereof. With my present invention, however, the said two circuits are not only independent of and distinct from each other, but in addition the operating or energizing circuit for the electro-magnet does not include the battery or any portion thereof, but doesinclude the secondary of the transformer or' induction-coil. With this arrangement the bat tery current is not employed for energizing the operating magnet of the pole changer. In this way the pole changer will, I find, operate efficiently on less current than those heretofore employed.

In the accompanying drawings Figure 1 is a diagram of a pole changer embodying the principles of my invention. Fig, 2 is a front elevation of the said pole changer. Fig. 3 is a. horizontal section on line 3-3 in Fig. 2. Fig. 4: is a detail plan view of the mounting or yoke which supports the armature and pendulum.

Referring to Fig. 1 my improved pole changer comprises an operating electromagnet A provided with an armature B, which latter is preferably mounted as here inafter described. The electromagnet and its armature are polarized by the permanent magnet M (Fig. 2) in the well-known manner in which ordinary alternating current ringer magnets are polarized. The armature B is provided with a downwardly-extending pendulum 6 having an adjustable weight b. This weight can be moved up and down to vary the frequency of the current produced by the pole changer. The battery C is divided into sections 0 and 0 The middle point or connection 0 between the two battery sections is connected with one terminal of the transformer or induction-coil primary D, the other terminal of this primary winding being connected directly with the said armature B. The said pendulum also carries a double ended switch contact 72 adapted to vibrate between the stationary contacts E nd F. These two stationary contacts are connected with the opposite poles of the battery C, as shown in Fig. 1. The secondary winding G of the said transformer or induction-coil is connected in series with the windings or energizing coils of the electroanagnet A, this circuit also preferably including a condenser H.

With this arrangement it will be seen that the energizing coils or windings of the electro-magnet A are connected in parallel with the telephone or other line I across which is bridged the call-bell J. In this way the alternating current produced in the secondary Gris supplied partly to the said operating magnet A and the balance goes to the line for operating the call-bell.

To start the pole changer it is only neces sary to swing the pendulum to one side, so as to close a circuit in one direction through the primary D. Suppose, for example, that the pendulum is pushed to one side until the contact I) touches the stationary contact E.

- Current then flows in one direction through the primary D, with the result that a discharge takes place through the condenser H and secondary G, and through the windings of the magnet A. The windings of the magnet A are so connected that current flowing through them in this direction strengthens the left-hand pole of the magnet and weakens the right-hand pole, with the result that the left-hand end of the armature B is drawn downward, carrying the contact 5 out of engagement with. the stationary contact E and into engagement with the contact F. As a result of the engagement of the contacts 6 and F a flow of current is set up in the primary winding D in the opposite direction, which induces a current in the secondary winding G which is in a direction opposite to the current 1nduced therein when the contact 6 engages the contact E. This current flows through the windings of the magnet A in a direction opposite to the first impulse described, and attracts the armature B in the opposite direction, which again reverses the current in the primary winding D. Thus an alternating current is supplied through the windings of the magnet A, with the result that its armature and pendulum are kept vibrating, and with the further result that the desired supply of alternating current is maintained in the line circuit. It will be understood, of course, that the resistance of the magnet A can be adjusted in such manner as to give the best results, as is also true of the capacity of the condenser H. In other words,

the resistance of the circuit including the which latter is in turn mounted upon a yoke L applied to the cores of pole-pieces of the said electro-magnet. This spring, it will be seen, has its end portions secured to the said yoke, and is arranged at right angles to the length of the latter. With this arrangement the said spring is given a torsional twist by the vibration of the armature and pendulum. The contacts E and F consist preferablyof springs which are mounted on brackets e and f, and which normally rest against the stationary springs or contacts 6 and F, the latter being also mounted upon the said posts or brackets. The stationary contacts or adjustable screws 6 and f bear against the contacts 6 and 7, as shown in Fig. 3, and in this way the vibration of the pendulum is subject to very little resistance. When the pendulum strikes the spring F the circuit is then from this spring through the adjacent spring 7, thence through the screw employed for connecting the secondary of the transformer in series with the coils or windings of the'elcctro-magnet, and for connecting the middle point of the battery in series with the primary of the transformer and the pendulum of the pole changer.

Vhat I claim as my invention is 1. In a pole changer apparatus, the combination of an electromagnet, a divided battery, a local battery circuit, a vibratingpendulum with means for accurately adjusting its frequency, said pendulum operated by the electromagnet and provided with means for reversing the flow of current in said circuit, said means comprising a spring provided with end and intermediate points of connection, a support engaging the said end points of connection on the spring, and

"means for securing the pendulum to the intermediate point of connection on the spring, said spring and pendulum included in said circuit, whereby the spring is first in series with one division of said battery and then in series with the other division thereof. I

2. In a pole changer apparatus, the combination of an electromagnet, a divided battery, a local battery circuit, means operated by the magnet for reversing the flow of current in said circuit, said means including a vibratory member with means for accurately ad usting its frequency, a stationary sup porting member, and a spring having its ends secured to one of said members and its middle portion secured to the other of said members, said spring and pendulum included in said circuit, whereby the spring is first in series with one division of said battery and then in series with the other division thereof.

3. In a pole changer apparatus, an operating electromagnet, a local battery circuit, vibratory means operated by the magnet for reversing the flow of current in said circuit, a transformer secondary winding connected in series with the coil of said magnet, the primary of said transformer being in said local circuit, and a divided battery having its middle part connected with said primary.

4. In a pole changer apparatus, the combination of an electromagnet, a polarizing permanent magnet assoclated therewith, a

battery, a transformer, a vibrating pendulum and connections for reversing the fiow of battery current through the primary of the transformer, and means for connecting the coil of said electromagnet in series with the secondary of the transformer.

5. In a pole changer apparatus, the combination of an electromagnet, a polarizing permanent magnet associated therewith, a battery, a transformer, a vibrating pendulum and connections for reversing the flow of battery current through the primary of said transformer, and means for connecting the coil of the electro-magnet in series with the secondary of the transformer, the said battery being divided into sections and having its middle point connected with one terminal of the said transformer primary.

6. In a pole changer apparatus, the combination of an operating magnet, a polarizing permanent magnet associated therewith, a pendulum operated by the magnet, a battery, a transformer, connections by which the vibration of the pendulum reverses the flow of current in the primary of the transformer, a line circuit including the secondary of the transformer, and a local secondary circuit including the coil of said operating magnet.

7. In a pole changer apparatus, the combination of an operating magnet, a polarizing permanent magnet associated therewith, a pendulum operated by the magnet, a battery, a transformer, connections by which the vibration of the pendulum reverses the flow of current in the primary of the transformer, a line circuit including the secondary of the transformer, a local secondary circuit including the coil of said operating magnet,,and a condenser in said local circuit, said battery being divided into sections and having its middle point connected with one terminal of the transformer primary.

8. In a pole changer, an electromagnet, a polarizing permanent magnet associated therewith, a pendulum vibrated thereby, spring contacts alternately engaged by the pendulum, resting contacts for said spring contacts, and adjustable contacts engaging said resting contacts.

9. In a pole changer apparatus, the combination of an electromagnet, a battery, a transformer, a vibrating pendulum with means for accurately adjusting its frequency and connections controlled thereby for reversing the flow of battery current through the primary of the transformer, and means connecting the electromagnet in series with the secondary of the transformer, whereby said electromagnet is energized by the alternating current in the secondary.

10. In a pole changer apparatus, the combination of an electromagnet, a battery, a transformer, a vibrating pendulum with means for accurately adjusting its frequency, and connections controlled thereby for reversing the flow of battery current through the primary of the transformer, means connecting the electromagnet in series with the secondary of the transformer, the said battery being divided into sections and having its middle point connected with one terminal of the said transformer primary, said magnet being thereby energized only by the alternating current in the secondary.

11. In a pole changer apparatus, the combination of an operating magnet, a pendulum with means for accurately adjusting its frequency, said pendulum operated by the magnet, a battery, a transformer, connections by which the vibration of the pendulum reverses the flow of current in the primary of the transformer, a line circuit including the secondary of the transformer, a local secondary circuit including the said operating magnet, said magnet being thereby energized only by the alternating current in the secondary.

12. In a pole changer apparatus, the combination of an operating magnet, a pendulum with means for accurately adjusting its frequency, said pendulum operated by the magnet, a battery, a transformer, connections by which the vibration of the pendulum reverses the flow of current in the primary of the transformer, a line circuit including the secondary of the transformer, a local secondary circuit including the said operating magnet, a condenser in said local circuit, said battery being divided into sections and having its middle point connected with one terminal of the transformer primary, said magnet being thereby energized only by the alternating current in the secondary.

Signed by me at Chicago, Cook county, Illinois, this 18th day of August, 1906.

CHARLES J. ERIOKSON.

lVitnesses:

J OHN ERICKSON, EDWARD D. FALES.

Sonics of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. C. 

